AS Edexcel - Vietnam help

K, two weeks til the exam I've got most of my revision done but the only problem I have is with writing "turning point" or "change" questions.

I really don't know how to answer the following:

1) How far do you agree that the Tet Offensive was a turning point?

- So what I know is that it was a political defeat for USA but a millitary victory... but what I don't understand is if it was a millitary victory how do I argue that the Tet Offensive was NOT a turning point?

2) How far do you agree that Johnson transformed the USA's involvement in Vietnam in he years 1963 - 1968?

- For this question I know how he did change the war, by escalating it, but how did he NOT change the war?

Halppppp